Rebecca was created along with April, Bobby, Charlotte, Delilah, Erica, Gideon, Jackson, Jamaica, Joey, Jonah, Julie, Laura, Mira, Rictor, Stephen, Tamara, Tomás by Zander Rice as part of the Transigen Project. Rice used genetic samples from mutants to create new embryos that were carried by captured women.
The mutant children were supposed to become soldiers, but were deemed failures after the creation of X-24. After the X-24 project was a success, and the X-23 Project a failure, Transigen scheduled all the other subjects for termination. With the help of the nurses, who had grown attached to the children, the mutant children escaped to find Eden, a safe haven for mutants in North Dakota, while Laura was spirited away and adopted by her nurse, Gabriela Lopez.
When Laura and Logan finally reach Eden, Logan collapses and the mutant children help him up to their hideout by lifting him up on a stretcher. Later on, Logan is nursed back to health by the mutant children. Gideon prepares a serum for Logan and asks Rictor if the dosage is good, but Rictor says that the dosage is too much, and tells Gideon to reduce it. Logan takes the vile of the Mutant Serum from Gideon, surprising the young mutant, and inquires as to where they got it from. Rictor explains it's from where the mutant children all came from: Alkali-Transigen.
The doctors would give it to the children when they would fight, as it makes a mutant stronger. Logan quickly points out that the serum makes mutants crazy and it could kill them, but Rictor says it won't if used in small doses before informing Logan that the serum is helping him heal. Logan asks where Laura is, and Bobby tells him that she's sleeping across the room and asks if Logan wants him to wake her up. Logan replies with a no. Afterwards, all the mutant children have dinner outside by a campfire.
- Empathy: Rebecca can sense, feel and understand the emotions of others.